The chemical industry requires the
mole to ensure that substances mix
at the ideal ratio for a reaction to be
The PTB (Physikalisch-Technische
Bundesanstalt) in Braunschweig,
Germany, supplies elemental soluti-
ons of known mass content to act
as transfer standards for calibration
of industrial applications.

[mol] ‘The MOLE is the amount
of substance of a system which con-
tains as many elementary entities as
there are atoms in 0.012 kilogram
of carbon 12.
When the mole is used, the elemen-
tary entities must be specified and
may be atoms, molecules, ions, elec-
trons, other particles, or specified
groups of such particles.’